Short straight-pull breech-action for military hand-firearms.



H. STAMM.

SHORT STRAIGHT PULL BREECH ACTION FUR MILITARY HAND FIREARMS APPLICATIuNHLED ocT.27.1914.

1,172,069. l Patented Feb.15,1916.

'2 SHEETS-SHEET)- H. STAMM. SHORT STRAIGHT PULL BREECH ACTION FORMILITARY HAND FIREARMS. APPLICATION FILED OCT. 27| i914.

1,172,069. I Patented F@b.15,1916;

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UMTED sTArEs PATENT c OFFICE 1 i Snom" STRAIGHT-PULL Bannon-crioN FonMILITARY HAND-manna.

Specification. of Letten Patent.

Patented Feb. 15, 1916.

Application tiled October 27, 1914. Serial 0.868,854.

To all whom it may concernv exact description o they invention, such aswill enable others skilled in -the art `to which it appertains to makeand use the same, reference being had to the accompanydrawings, and toletters or figures of' 1n reerence marked thereon, which form a part Vofthis specication.

Straight pull breech action in which the i breech bolt, fitted -withlockingnibs, can be turned by a turning member mounted on it,

a so-called grip, or a rectilinearly movable locking member in thebreech frame, in order to effect the `lockin andj unlocking, havealready been made own. In these breech action systems the locking nibsare fitted in front on the breech bolt head, owing to which the turningmember, the -grip or the locking member has` to be pushed over the boltfrom behind.

In straight pull breech actions in which the breech bolt can be turnedby a locking member which moves to ,and fro in. a straight line, spiralgrooves must be provided for the purpose of rotating thebreech bolt,these grooves being cut in the surface'4 of the bolt, the consequence ofwhich is that the back endof the bolt is very much weakened on the onehand by these grooves, and on the other hand bythe principal bore in thebreech bolt which serves to receive the striking mechanism or device,and.' also by a screw-thread outside or inside the back end of the bolt,vwhich serves toreceive a nut or guide socket. If this weakened bolt endis furthermore provided on its front face with lnotches in which, forthe purpose of automatically grlpping and securing the striking p1nasecuring'member connected, with ythe latterY must move,r this weakenednotched surface at the rear v end of the Abolt y will 'rapidly wear awayand in `course of time lose its shape. Furthermore, the provision of thelookin nibs on the front-end of the breech bo t involves an extremelylon breech mechanism,

because behind the locklng nibs, directly in front of theloading-aperture back su ports must also be provided on the breech`rame, thus entailing considerable lengthening of eALLEN, sw1TzEB.LANn,assIeNon 'ro THE nimmer from saunas., or aaron', swrrznnmrm.

the movement of the whole of the breech mechanism when opening andclosing it.

According to the present inventionthese drawbacks are to be remedied byarranging the locking nibs on the back part of the breech bolt andmaking it posslble to push the 'locking member from the front on to thebreech bolt so that the rear end of the bolt can without hindrance b emade of sulicient strength, and means are further provided to enable thefront end of the bolt in the closed position of the breech mechanism',to project only a small. amount into the breech frame in front of theloading aperture, so that the breech action and its Y movements areextremely short.

A constructional example of the Ainvention is illustrated in theaccompanying drawings, in which:

Fi re 1 is a vertical longitudinal section through the locked breechmechanism after firing a shot. Fig. 2 is a horizontal-longitudinalsection through the breechaction ,shown in Fig. 1. Fig. 3 is a`horizontal section through the breech actonin its open and drawn backposition;v Fig. 4 is a vertical section of a safety' device combinedwith the trigger for securing the breech bolt. Fig. 5 is a section onthe line A-B of Fig. 1 with the safety device in side elevation.

As shown, the military firearm possesses a straight pullybreechy actionwhich is movable in a straight line to and fro in astationarybreechframe 1 rigidly fixed to the a handle 6, by meansof which thelocking sleeve or the entire breech action can be actuated. Forreceiving the locking nibs 4 when locking theV breech mechanism, thereare provided at the rear end of the breech frame l, the two lockingrecesses 7 formed with rear abutments 8 (Figs. 1 and 4).

In order to impart the necessary rotary movement to the breech bolt forlocking and unlocking, the breech bolt is formed with helical grooves 9into which the locking sleeve 5 projects with corresponding helical lribs 10. 'The locking sleeve 5 has such longitudinal movement on thebreech bolt 3, that when shifted on the bolt it imparts to the latter aquarter turn of 90, the nibs 4 being turned in to the recesses 7 or outof them. The movement of the locking sleeve on the breech bolt islimited in its back-v ward movement on the breech bolt by the stop face3 on the breech bolt (Fig.,1) and is limited in its forward movementthereon by a nose 1l on the cartridge extractor 12 of the breech bolt,the said nose extending into a recess 5 in the locking sleeve 5 (Figs. 2and 3).

The locking sleeve 5 is guided by lateralv ledges 13 in correspondinglongitudinal grooves 14 in the breech frame 1. These grooves 14, in therear ends of which the nibs 4 can also be guided, are in connection withthe recesses' 7 so that the Ynibs can be turned out of the groovesl14into therecesses and vice versa out of the recesses into the grooves. Inorder to prevent the complete drawing out of the breech action from thebreech frame when opening the breech for the purpose of loading, thereis fitted at the rear end of the breech frame 1 a breech holder whichconsists of a lever 15 mounted at the side of the breech frame, andformed y with a nose 16 which 'projects into the latter, under theaction of a, spring. There is also provided at the front end of thebreech bolt a recess 17, into which the nose 16 of the lever 15 can snapwhen the breech is open and thus prevent the breech action from beingcompletely drawn out of the frame (Fig.

In the breech bolt 3 the striking device is mounted; it consists of thestriking pin 18 which carries at its front end. the removable tip 19 andat its rear end -a head 20, formed with .a lateral -safety arm 21 (Fig.2). The striking pin is ,under the action of the main spring 22 whichbears at one end against the striking pin tip 19 and at the other endagainst a sleeve 23 screwed into the breech bolt 3 (Figs. 1-3). Thissleeve'has a rear cylindrical socket 24 to receive a safety sleeve 25,which is in turn designed to receive the striking pin head 20.

The safety sleeve 25 and the socket 24, which serves as guide for A.thesafety sleeve, have proper for the, arm 21of the striking pin.

The notches in the guide socket 24 are only provided to allow the arm 21to enter the notches in the safety sleeve; they are deeper than thenotches 26 and 27 (Figs. 2 and i The sleeve 25 is coupled to thestriking pin by means of-a stud 28 mounted in it, which projects into agroove 29 in the striking pin head 20. The groove 29 is semiannular toallow of rotating the striking pin relatively to the safety sleeve; atits end it is made wide enough to permit of drawing back thestriking'pin in the safety sleeve 25 for the purpose of securing it. Aledge 25 (Fig. 4) Oprovided on the lower face of the sleeve 25 projectsinto a longitudinal slot in the guide socket 24 and at the bottom ofthis ledge there is the lug 30 and at the front end of the ledge, thesafety nose 31 which, for the purpose of securing the breech bolt 3,works in conjunction with two notches 32 and 33 at an angle of 90 toeach other provided at the back end of the breech bolt. The notch 32 isdeeper than the notch 33 (Fig. 2) to enable'the striking pin to shootforward with the safety sleeve on ring. The notch 32 on the other hand,in which the nose 31 lies after unlocking the breech bolt, and which isconnected withv the notch 32 by an oblique surface, serves the purposeof keeping the striking pin in its secured drawn back position.

34 is the spring cartridge ejector which is itted in a verticallymovable manner beneath the breech bolt, and for the purpose of ejectingthe empty cases of the fired carders it impossible to fire the shotbefore the I breech bolt is completely locked.

42 is the loading aperture (Fig. 3). Tliemethod of handling and the'operation of the firearm is as follows: The breech action is shown inFigs. 1 and 2 in the lockedposition after firing a shot, the lockingsleeve 5 is in its front position on the breech bolt and the safetysleeve 25 pro 'ects with the nose 31 `into the deeper notch 2 at theback end of the breech bolt, while the safety arm 21 of the striking pin18 isin the deeper notch 26 of the safet sleeve 25, z'. e. in theunsecured position. o open the breech mechanism, the lookin sleeve 5 isdrawn back; this, in the rst instance, owing to the helicirl grooves 9and the screw pieces 10, causes the breech bolt 3 to turn, that isunlocks the breech action, and owing to the transverse step on thelocking nibs 4, the empty cartridge case which has been fired is verymuch loosened. Toward the end of the releasing movement, the back endofthe locking sleeve strikes against the stop surface 3 of the breech,boltnnd the locking nibs 4 pass out of the recesses-,7 in the breechframe into the uide grooves 14, and from -tliis moment t e Wholei-breechaction is drawn back behind the loading aperture 42 where it is heldfast by the lateral breech helder 15, which rejects into the recess 17at the front end o? the breech bolt, (Fig. 3). At the same moment thecartridge case which was just loosened is thrown out bythe ejector 34provided beneath the `leerling aperture, and duri the return movement ofthe locking sleeve, z. e. during the releasing rotin tion of the breechbolt, the striking pin 18 is drawn farther back. The last operation iseffected by the safety sleeve 25 which is shifted back by the risingslopn surface between the notches 32 and'33 0.3) at the buck end of thebreech bolt, engaging the nose 31, which under the pressure of the mainspring. snaps into the shallower safety notch 33 at'the end of saidsurface, owing to which the striking pintip 19 is also drawn away fromthe cartridge percussion cap and held or secured in thisdrawn backposition. At the saine time the breech bolt 3 is in this way preventedfrom making an unintended further turn. rW'hen closing the breechaction, owing to the rectilinear forward push of the locking sleeve 5,the `breech bolt 3 iny the first place forces a .fresh cartridge,pressed up from the magazine,` into the barrel and at the saine time,when ythe breech action is forced forward, the striking pin lug` 30 onthe safety sleeve is held by the ti'i er lug 40 and the main spring 22putmun er` tension. Vhcn the'breech bolt `strikes behind tlie cartridgeat the back cnd'of the barrel, a mere forward thrust ofthe lockingsleeve suices to `turn the breech bolt'again through the helical grooves9 and the screw` pieces 10, and consequently the locking nibs will againreach their locking position in the I arrangement against firing. f

recesses 7, und the nose `31 von the safety `sleeve.limilieen turnedoutvol'. the sl'izillowcr -notch nud willl lio opposite'thc deeper notch32 :it the buck rml of the breech bolt, into shallower notch 27 of thesafety sleeve 25,

owing to which the striking pin tip 19 is drawn away from the cartridgecap and is held in this position by the main spring 22.

In the straight pull breech action above described and illustrated, thearrangement 1n which the locki nibs are provided at the back end of thereech bolt and the ro tary member, i. e. .the locking sleeve 5 can bethrust vfrom the front over the breech bolt, permits of making the rearend of the breech bolt of sufficient strength without any hindrance, andthe front end of the breech bolt needonly project by a smell amount infront of t e loading aperture, into the breech frame. Owing to thesemeasures, o

pin 18 can, as already mentioned,A

considerable strengthening and shortening of the breech action andmobility of the breech action when o ning and closing it for the purposeof ceding, are secured. Owing to the strengthening of the rear end ofthebreech bolt, it is also made possible to utilize the guidesleeve as backsupportfor the main spring und make the rear parts of the striking pinand safety mechanism of sulicient strength. The arrangement of thelocking nibs at the rear end of the breech holt, r. ict-.hindv theloading aperture, also allows of'fitting the breech safety pieces 4, 41,Iat che most favorable possible point` Owing to the fact that whenactuating the trigger, the cheek 41 on the sear 39 cnn rise up frombelow, together with the breech nib t lying below, the breech bolt is,when the shot is` fired, n prevented by the cheek 41` fromturnng backand thus effecting automatic unlocking. I f, when the shot is i red thebreech bolt should not be fully locked.

proper locking position, it is impossible to pull the senr down to firetheshot,because its cheek 41 cannot then rise into the mierture in thebreech frame 1 covered b v the lower locking nib, and therefore thefiring ofthe shotfwhen the breech action is not completely locked isprevented, so that the above breech su fety arrangement againstunlocking of the breech action serves ut thv suine time as an absolutelyreliable safety The taking apart und.`l putting together ngain of thebrceuhhnction can bo ell'cctorl with gri-.ut facility owing to thesimplicity "i ing pin tip is then coupled to the striking of the desiAfter drawing the breech action out o the breech frame, the sleeve 23together with the striking device, are unscrewed from behind out of thebreech bolt 3, whereupon the striking picn tip 19 is uncoupled' from thestriking pin 18 and can now be removed together with the main spring.Hereupon the striking pin 18 is by its arm 21, together with the safetysleeve, drawn from behind out of the guide socket 24 and the entirebreech action has thus been taken apart. It is not necessary that thelocking sleeve 5 should also be slipped forward over the breech boltexcept in the case of general cleaning or greasing.I In this case onlythe spring cartridge extractor 12 is presseddown slightly by its 'nose11, whereupon the locking sleeve can straightway be slipped off thebreech bolt.

Putting together is effected in the inverse' order with the same easeand simplicity. The striking pin 18 together with the sleeve 25 arepushed from behind into the guide socket 23, 24. Hereupon the mainspringis pushed from the front on to the nlong front part of the striking pinand the strikpin 18 in front of the main spring. The whole is nowscrewed into the breech bolt from behind by means of the 'guide`socket,`

whereupon the breech action can straightwav be pushed back into thebreech frame.

What I wish to claim is:

1. In a straight pull breech action for re' arms, a breech frame, abreech bolt having integral locking nibs on its rearend adapted toengage recesses in the back part of the breech frame, a locking sleeveguided rectilinearly in the latter and on the breech bolt in front ofthe nibs, and means on the sleeve and bolt for locking the latter in theframe.

and bolt for lockingthe latter in the frame,

and means on the breech bolt to limit the backward and forward movementof thev locking sleeve on the bolt. I

3. In a straight ppll breech action for firearms, a breech fragile, abreech bolt having integral locking nibs on its rear end adaptedto"engage recesses in the back part of the breech frame, a lockingsleeve guided rectilinearly in the latter and on the breech bolt,helical ribs and grooves on the -sleeve and bolt for locking the latterin the frame, a

spring cartridge extractor at the front endv of the breech bolt having aprojecting nose engaging a recess at the front end of the' lockingsleeve,` and a stop on the rearpart of the breech bolt to limit thebackward movement of the sleeve on the breech bolt.

4. In a straight pull breech action for firearms, a breech frame, abreech bolt having integral locking nibs on its rear end adapted toengage recesses in the back -part of the breech frame, a locking sleeveguided rectilinearly in the latter and on the breech bolt, said sleevehavingr helical ribs ena'aginghelical grooves in the bolt for lockingthe latter in the frame, means on `the breech bolt for limiting thebackward and' forward movement of the sleeve on the bolt, and means tolimit the opening movement of the breech action.

5. In a straight pull breech action for firearms, a breech frame, abreech bolt having.

integral lockingnibs on its rear end adapted to engage recesses in theback part of the breech frame, aalocking sleeve guided rectilinearly inthe latter and on the breech bolt,

limiting kthe backward and forward movement of the sleeve on the bolt,and a spring actuated member arranged on the frame to engage a recessinv the front end of the breech boltfwhen the latter is near the end 'ofits rearward movement.

6. In a straight pull breech action for lirearms, a breech frame, abreech bolt having integral locking nibs on its rear endadapted toengage recesses in the back part of the breech framefa locking sleeveguided rectilinearly in the latter and on the breech bolt, means on thesleeve andbolt for locking the latter in the frame, a searmechanism, andmeans for preventing the unlocking of the breech bolt o-n firing and toprevent the operation of the Sear when the breech action is unlocked'. A

7. In a straight pull breech action foilirearms, a breech frame, abreech bolt having breech frame, a locking sleeve guided recti linearlyin the latter, and on the breechbolt,

- integral locking nibs on its rear endadapted to engage recesses in theback part of the means o-n the sleeve and bolt for locking the l latterin the frame, aA sear mechanism, and

an upwardly projecting member arranged to be moved by the scar into thecasing adjacent one of the locking nibs to prevent un l locking ofthebreech'bolt on firing.

8. In a'straight pull breech action'for fire-- arms, a breech frame,abreech bolt having integral lockingnbs on its rear end adapted toengage recessesin the back part of the breech frame, a locln'ng sleeveguid'edrectilinearly in the latter and on the breech bolt in front ofthe nibs, means on the sleeveand4 bolt for locking the latter in theframe,

means on the breech bolt to limit the backward and forward movement ofthe lockingy sleevey onithe bolt, means to limit the openas my inventionIy have signed my name in ing movement of the breech action, andpresence of thesbscrbin Witnesses.

means tok prevent VVthe unlocking of the ANS STAMM. breech bolt u onfiring sind to prevent-,the Witnesses: 5 operationof t e'lsear when thebreech action CARL KAUFMAN, is unlocked. R. H. WILLIAMS.,

In testimony that I claim thewfuoregong. FRANK 'Eliminating

